High Wind Watch 4, NWS Glasgow, MT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
904 PM MDT SUN MAR 25 2012

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
UPDATED THE FORECAST TO INCREASE THE CLOUD COVER AS PACIFIC
MOISTURE IS BEING SHOT NORTHWARD BY UPPER TROUGH OVER BAJA
CALIFORNIA. UPPER TROUGH WILL BE PUSHED OVER THE SIERRA NEVADA
MOUNTAIN TONIGHT AND IT WILL HEAD TOWARDS THE NORTHERN PLAINS AS
MORE OF AN OPEN WAVE THAT HAS A NEGATIVE TILT TO IT. THIS WILL
LEAD TO SHOWERS AND A FEW THUNDERSTORMS MONDAY AFTERNOON AND
EVENING. RSMITH

PREVIOUS DISCUSSION...SYNOPTIC SET UP... A TROUGH OF COLD AIR EXTENDS
FROM THE HUDSON BAY DOWN INTO THE MIDWEST. A WARM RIDGE RUNS UP
THE HIGH PLAINS FROM TEXAS INTO COLORADO AND THEN TILTS BACK
TOWARD THE MONTANA FRONT RANGE. TO THE WEST A WELL AMPLIFIED
TROUGH EXISTS FROM THE COASTLINE OF SOUTHERN CALIFORNIA UP THROUGH
BRITISH COLUMBIA. ANOTHER TROUGH EXISTS JUST SOUTH OF ALASKA IN
THE NORTH PACIFIC. BEHIND THE PREVIOUSLY MENTION ONE.

TONIGHT... THE RIDGE OVER THE HIGH PLAINS WILL CONTINUE TO BUILD
IN WARMTH AND AMPLIFY. MOISTURE TRAPPED UNDER THE RIDGE AT THE
SURFACE MAY BE CAPABLE OF FORMING LOW LEVEL STRATUS AGAIN DURING
THE MORNING HOURS WHICH COULD KEEP NIGHT TIME LOWS FROM BOTTOMING
OUT FOR AREAS IMPACTED. A WARM FRONT LIFTING OVER FAR EASTERN
MONTANA AND THE DAKOTAS MAY BE ABLE TO PRODUCE EARLY MORNING
SHOWERS BUT THIS IS NOT LIKELY AT THIS TIME.

MONDAY THROUGH MIDNIGHT... THE UPPER LEVEL RIDGE WILL SLIDE EAST
AS THE EXTRA ENERGY AT THE TIP OF THE CALIFORNIA TROUGH ROUNDS AND
GETS FLUNG UP WILDLY INTO WYOMING. THE CONTRAST OF A COLD
ENERGETIC SHORTWAVE AND A HOT THERMAL RIDGE WILL SPIN UP A SURFACE
LOW AND PROBABLY SPARK OFF THUNDERSTORMS ACROSS EASTERN MONTANA.
HOWEVER... A LARGE SWATH OF AREA JUST NORTH OF THE LOW IS
ANTICIPATED TO BRIEFLY SKIRT BY WITH NO SHOWERS DURING THE MID DAY DUE
TO A VERY STRONG THERMAL CAP THAT WILL PRECLUDE SHOWERS UNTIL THE
EVENING HOURS. CAPE LOOKS TO BE THIN AND DRY AIR ENTRAINMENT WILL
LIMIT THE STRENGTH OF ANY INITIAL CELLS. BY THE LATE AFTERNOON AND EARLY
EVENING HOURS PACIFIC MOISTURE SHOULD BEGIN PUMPING IN AND
SHOWERS SHOULD SPREAD OUT IN COVERAGE AND ENOUGH CAPE MAY BE LEFT
TO THROW OUT A COUPLE BOLTS BEFORE MIDNIGHT. SHOWERS SHOULD BECOME
FAIRLY STRATIFORM BY TUESDAY MORNING AS A COLD FRONT SLIDES DOWN
THE BACK SIDE OF THE LOW. LARGE QPF TOTALS OF A TENTH TO A HALF
INCH WILL BE POSSIBLE WITH ANY HEAVY SHOWERS ESPECIALLY ACROSS THE
YELLOWSTONE VALLEY.

TUESDAY MORNING AND AFTERNOON... A COLD FRONT WILL MOVE THROUGH THE REGION
AND WINDS BEHIND THE FRONT WILL TURN OUT OF THE NORTHWEST DRAWING
DOWN COLD AIR AND SWEEPING THE RAIN SHOWERS OFF TO THE EAST. THIS
WILL BE A GRADUAL PROCESS THAT WILL TAKE ABOUT 12 HOURS. STRONG
WINDS BEHIND THIS SYSTEM WILL NOT BE GRADUAL HOWEVER... AND DUE TO
A STRONG PRESSURE GRADIENT AND CAA COULD REACH UPWARDS OF 25 TO 30
MPH SUSTAINED WITH 35 TO 40 MPH GUSTS BEFORE LETTING UP DURING
THE EVENING. GAH

.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
12Z MODELS RUNS IN A LITTLE BETTER AGREEMENT WITH THE TIMING OF
THE SHORTWAVES IN THE EXTENDED PERIOD. UPPER RIDGE SLIDES ACROSS
THE NORTHERN PLAINS ON WEDNESDAY FOR A RETURN TO WARM AND DRY
WEATHER. A WEAK SHORTWAVE PUSHES A COLD FRONT THROUGH THE STATE ON
WEDNESDAY NIGHT. MODELS TRENDING DRY WITH THE FRONT AND CONVECTIVE
PARAMETERS DIMINISH QUICKLY IN THE EVENING SO REMOVED MENTION OF
THUNDER. CONFIDENCE DECREASES FOR THE REMAINDER OF THE FORECAST
PERIOD WITH EC MORE PROGRESSIVE BRINGING SHORTWAVES ACROSS THE
REGION THEN THE GFS/GEM WHICH MAINTAIN DRY WARM SOUTHWEST FLOW
INTO THE WEEKEND. SPLIT THE DIFFERENCE AND KEPT SOME POPS WITH
GFS WARM FRONT/EC COLD FRONT PASSAGE ON FRIDAY...THEN BOTH MODELS
BRING A STRONGER COLD FRONT THROUGH THE REGION ON SATURDAY
NIGHT/SUNDAY. EBERT

PREVIOUS LONG TERM DISCUSSION...THE EXTENDED BEGINS WITH A SHORT
WAVE RIDGE IN PLACE OVER MONTANA. THE GFS AND EC ARE IN GOOD
AGREEMENT ON THIS FEATURE. THE RIDGE MIGRATES TO THE EAST PUTTING
MONTANA IN SOUTHWEST FLOW ALOFT. FROM DAY 5 AND BEYOND THE EC AND
GFS HAVE DIFFERENT TIMING AND POSITIONING OF FEATURES MOVING
THROUGH THE UPPER FLOW PATTERN.

CONFIDENCE IS LOW IN PINNING DOWN THE EVENTS THIS WEEK WITH THE
MODEL DIFFERENCES ON TIMING... HOWEVER THE OVERALL PATTERN IS
WESTERLY TO SOUTHWESTERLY WITH CHANCES OF WEAK CONVECTION WITH
STRONGER SHORTWAVES AND FRONTS. OVERALL NOT ANY BIG TEMPERATURE
SWINGS ARE EXPECTED THROUGH THE PERIOD.

FOR THE SOLUTION IN THE EXTENDED LEANED ON A HEAVY EC CONSALL
BLEND FOR FORECAST ELEMENTS WHICH KEPT WITH THE CURRENT FORECAST
TREND. PROTON

&&

.AVIATION...
MOSTLY VFR. EASTERLY WINDS WILL REMAIN ABOVE 10 KTS OVERNIGHT...
AND STRONGER AT KGGW AS A LARGE STORM SYSTEM DEVELOPS OVER
WYOMING. WITH THE EAST WIND KEEPING MOISTURE OVER THE REGION COULD
SEE SOME PATCHY MVFR CONDITIONS AGAIN IN THE YELLOWSTONE VALLEY ON
MONDAY. AS THE WYOMING STORM MOVES NORTH EXPECT FLIGHT CONDITIONS
TO DETERIORATE WITH RAIN SPREADING ACROSS THE REGION MONDAY NIGHT.
WINDS WILL ALSO BE SWITCHING TO THE WEST OR NORTHWEST AND
INCREASING. RAE

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 3 PM MDT MONDAY FOR FORT PECK LAKE.

FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR MTZ122.

&&

WEATHER.GOV/GLASGOW

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GLASGOW MT
237 PM MDT SUN MAR 25 2012

MTZ023>027-261030-
MCCONE-RICHLAND-DAWSON-PRAIRIE-WIBAUX-
237 PM MDT SUN MAR 25 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
MONTANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A LAKE WIND ADVISORY IS IN EFFECT FOR FORT PECK LAKE THROUGH NOON
TOMORROW FOR SOUTHEAST WINDS OF 15 TO 25 MPH WITH GUSTS UP TO 30
MPH.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A FIRE WEATHER WATCH IS IN EFFECT FOR ZONE 122 FROM NOON MONDAY
THROUGH 9 PM MONDAY EVENING FOR SOUTHEAST WINDS OF 20 TO 30 MPH
SUSTAINED WITH GUSTS UP TO 40MPH... RELATIVE HUMIDITY OF 20
PERCENT... DRAMATIC WIND SHIFT... AND POSSIBLE LIGHTNING STRIKES
FROM PASSING THUNDERSTORMS.

A STRONG COLD FRONT WILL PASS THROUGH THE AREA MONDAY EVENING.
AHEAD OF THE FRONT EXPECT SCATTERED SHOWERS AND THUNDERSTORMS. AS
THE FRONT PASSES THE WINDS WILL SHIFT TO THE NORTHWEST AND
INCREASE TO BETWEEN 30 TO 40 MPH WITH GUSTS NEAR 50 MPH. THE
STRONGEST WIND SPEED WILL BE SOUTH OF THE MISSOURI RIVER. YOUNG
LIVESTOCK COULD BE IMPACTED BY THE RAIN...COLD AIR AND STRONG
WINDS THROUGH TUESDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

MTZ016>022-059>062-261030-
CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY-
DANIELS-SHERIDAN-WESTERN ROOSEVELT-PETROLEUM-GARFIELD-
NORTHERN PHILLIPS-SOUTHWEST PHILLIPS-NORTHERN VALLEY-
EASTERN ROOSEVELT-
237 PM MDT SUN MAR 25 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
MONTANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A LAKE WIND ADVISORY IS IN EFFECT FOR FORT PECK LAKE THROUGH NOON
TOMORROW FOR SOUTHEAST WINDS OF 15 TO 25 MPH WITH GUSTS UP TO 30
MPH.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A STRONG COLD FRONT WILL PASS THROUGH THE AREA MONDAY EVENING.
AHEAD OF THE FRONT EXPECT SCATTERED SHOWERS AND THUNDERSTORMS. AS
THE FRONT PASSES THE WINDS WILL SHIFT TO THE NORTHWEST AND
INCREASE TO BETWEEN 30 TO 40 MPH WITH GUSTS NEAR 50 MPH. THE
STRONGEST WIND SPEED WILL BE SOUTH OF THE MISSOURI RIVER. YOUNG
LIVESTOCK COULD BE IMPACTED BY THE RAIN...COLD AIR AND STRONG
WINDS THROUGH TUESDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.